Re: [Qemu-devel] [PATCH] qemu-config: Accept empty option values

[Paolo Bonzini]

On 08/04/2015 20:16, Eduardo Habkost wrote:
> Currently it is impossible to set an option in a config file to an empty
> string, because the parser matches only lines containing non-empty
> strings between double-quotes.
> 
> As sscanf() "[" conversion specifier only matches non-empty strings, add
> a special case for empty strings.
> 
> Signed-off-by: Eduardo Habkost <address@hidden>
> ---
>  util/qemu-config.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/util/qemu-config.c b/util/qemu-config.c
> index 2d32ce7..9f9577d 100644
> --- a/util/qemu-config.c
> +++ b/util/qemu-config.c
> @@ -413,7 +413,8 @@ int qemu_config_parse(FILE *fp, QemuOptsList **lists, 
> const char *fname)
>              opts = qemu_opts_create(list, NULL, 0, &error_abort);
>              continue;
>          }
> -        if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2) {
> +        if (sscanf(line, " %63s = \"%1023[^\"]\"", arg, value) == 2 ||
> +            (value[0] = '\0', sscanf(line, " %63s = \"\"", arg) == 1)) {
>              /* arg = value */
>              if (opts == NULL) {
>                  error_report("no group defined");
> 

Acked-by: Paolo Bonzini <address@hidden>